Red Hulk is an alias used by two different fictional characters in comic books published by Marvel Comics, American generals Thaddeus "Thunderbolt" Ross and Robert Maverick. The first incarnation of the Red Hulk (also known as Rulk) first appeared in the Hulk series that debuted in 2008. The 2010 "World War Hulks" storyline reveals this being to be United States Army General Thunderbolt Ross, the father-in-law and longtime nemesis of the original Hulk, Bruce Banner.
The story reveals that the organizations AIM and Intelligencia gave Ross the ability to transform into the Red Hulk, and that he did so to better fight the original Hulk.
The origin of the second Red Hulk appears in the 2017 debut issue of USAvengers. Four-star General Robert Maverick is selected for his genetic profile to create a being that is "halfway to the Hulk". A device called the Hulk Plug-In, created by Avengers Idea Mechanics (a legitimate technology company created from the remnants of the defunct supervillain organization Advanced Idea Mechanics), is implanted in Maverick's wrist. When activated, it turns him into a variation of the Red Hulk for approximately an hour every day and a half. Unlike the Thunderbolt Ross version of the Red Hulk, Maverick retains his mustache in his Hulk form and wears sunglasses. He joins the U.S. Avengers.